An extensive search of patents, textbooks, and technical journals has revealed that there is no device nor suggestion of such, that utilizes a slip-clutch principle nor magnetic slip-clutch nor which measures change of direction of an object moving in non-linear and/or arbitrary varying manner. Such motions may be of an object moving in a nonlinear, slow movement such as the breathing of a child over a long period of time, or of ocean waves, or winds. In electronics, peak and cross-over detectors can measure sinusoidal and some bounded waves. However, in general they cannot follow an arbitrary waveshape. In the physical domain, there can be thousands of applications of such a detector not heretofore available. Such detector, together in combination with conventional electronic existing prior art, can be readily utilized to monitor the breathing of a small child for example. Heretofore, breathing measuring methods outside of a closed incubator include radar and sonar techniques, and restrictive belt resistance sensors, and methods in which the patient is wired to a machine. Sound sensors are also being studied. However, there is no safe nor accurate, low cost device nor method which heretofore could measure a child or adult in his breathing without disturbing him or exerting significant force on him. No device could be placed on a sleeping child who is under a blanket and in a second could give an accurate measurement of events of breathing.
U.S. Pat. No. 4,057,904 by Vrabel discloses the sole device which measures a similar type of motion; however, it measures distances and exerts large forces and operates over a large hysteresis loop, of large magnitudes. It is designed for a large differential in X and a variable L, and measures the variation of distance between freight cars. It is a rugged, heavy-duty device, and there is no way a miniature version thereof could pick-up differentials of X anywhere approaching as small as 0.005 inch nor at any force that might approach as small as or less than an ounce. It additionally could not survive service of anywhere near 50 million operations. Not even with aerospace technology and antibacklash gearing could this patent's device be considered a delicate measuring instrument.
For use in delicate measurements, a direction change detector must operate with a very small window (in minimum range) of detection-sensitivity, in order to accurately switch on the occurrances of the instantaneous peaks. However, a slight hysteresis is required for stability. Acturally, the above-noted Vrabel's patented device is the exact "opposite" to that of the present invention of this application; Vrabel's device works mostly in the linear region, and rarely slips on its clutch, whereas, the present inventive direction sensor--as shall be later described, constantly slips on its clutch-mechanism as a critically required part thereof permitting movement over a large range of a movement the direction of which is being detected as a movement.
Another patent that merely superficially resembles one of the embodiments of the present invention, to be later described, is the accelerometer of Forsberg U.S. Pat. No. 3,731,542.